Photographic color correction process using 2-azo-1-naphthol dyes



Nov. 18, 1958 K. E. WHITMORE ETAL I 2,

PHOTOGRAPHIC COLOR CORRECTION PROCESS USING Z-AZO-l-NAPHTHOL DYES Filed Sept. 2a, 1956 Fig.

COLORLESS YELLOW COUPLER COLORLESS MAGENTA COUPLER 4- A20 -5 PYRAZOLO/VE COUPLER Z-AZO-l-IVAPHTHOL COUPLER COLORLESS CYA/V COUPLER SUPPORT DENSITY IO L06 EXPOSURE KEITH E. .WH/TMORE EDWARD T PESCH INVENTORS ATTORNEY 8 AGENT United States Patent "ice PHOTOGRAPHIC COLOR CORRECTION PROCESS USING Z-AZD-l-NAPHTHOL DYES Keith E. Whitmore and Edward T. Pesch, Rochester,

N. Y., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application September 28, 1956, Serial No. 612,681

7 Claims. (Cl. 96-9) This invention relates to photography and more particularly to the preparation of color correction images in photographic emulsion layers by means of colored coupler compounds.

The use of colored coupler compounds in photographic color correction processes is well known, as shown, for example, by Hanson U. S. Patent 2,449,966, Graham et al. U. S. Patent 2,657,134, Vittum et a]. U. S. Patent 2,428,054, and Glass et al. U. S. Patents 2,455,169 and 2,521,908.

Typical colored couplers thus previously known are the 4-azo-l-naphthol couplers which have the property during color development of an exposed silver halide emulsion layer, of splitting at the azo linkage to release a phenolic fragment which reacts with the oxidation products of the color developing agent to produce a dye having a color different from the original colored coupler. The original colored coupler retains its color in the unexposed regions of the emulsion layer and thus may serve as a color correction mask or image.

Accordingly, the colored coupler can be used as the sole coupler in an emulsion layer of a multilayer color film or as is the more usual practice, the colored coupler is supplemented by a colorless image-forming coupler, for example, as shown in U. S. Patent 2,428,054 above. In this case, for example, a yellow-colored coupler which forms a magenta dye on coupling with the developing agent, may be used together with a colorless magentaforming coupler in a green-sensitive emulsion layer of a film. Color development of the locally exposed emulsion layer produces a composite magenta-dye image from the two couplers in the exposed areas, whereas in the unexposed area the yellow-colored coupler remains unchanged to serve as a color correction mask.

We have discovered that certain 2-azo-1-naphthol dyes can be used as colored couplers in colorfilms in conjunction with colorless couplers in the manner described. However, the 2-azo-1-naphthol dyes do not function in the same manner as do the usual colored couplers such as the 4-a'zo-l-naphtho1 colored couplers, That is, the 2-azo-1-naphthol. couplers upon reaction with the oxidation products of the color developer, yield yellowish to brown or practically neutrally colored productsof low tinctorial power rather than cyan dyes which might be expected if the mechanism was the same as takes place with the 4-azo-l-naphthol couplers. Furthermore, the fact that upon color development the 2-azo-1-naphthol dyes yield products of low tinctorial power realizes a long- I felt need for colored couplers which will couple to substantially colorless or neutrally colored products which will not adversely affect dye images produced in the same region from colorless couplers. It is probable that this mechanism is due to the failureof the 2-azo-1-naphthol couplers to split at the 2-azo group during color development, and thus fail to provide a naphtholic fragment for coupling with the oxidized color developer.

The mentioned property of the 2-azo-1-naphthol dyes can thus be utilized to provide masking images havinga naphthol nucleus.

2,860,975 Patented Nov. 18 1958- effective for the production of masking images in photo-- graphic emulsion layers are the 2-azo-1-naphthol dyes which are not substituted in the 3- or 4-po sitions of the That is, the'following dyes having sulphonic acid groups in the 3- or 4-positions have not been found to be efiective in the preparation of masking images as described.

OH CH; OH; OH

SOaNfl SO Na N=N I SOaNa OaNa NH: OH SOgNa NzS- N=N O CnHrs S 3N8 BOzNa NH: OH OCmHzs NEO S SOzNa NHCOCH;

OH (])C1:H25

NaOaS --S0 Na NH; on "some NaOsS SO Na The 2-azo-1-naphthol dyes free of substitutents in the 3 or'4 nuclear positions,,such as the following, are useful in the invention. v v 1 NH. OH 001m B sN I Magenta 3,,

(II) N H: OH OH IIIHI @N:N O N=N l S ;Na S 0 :Na

Blue-magenta (III) CHIIGONH 0H 00mm S OzNa Magenta ITIH; 0H (FOE: OCH: OH NH:

S O 3N8 S63N8 Blue, Shultz No. 509 (V) O H S O N a Red, Shultz No. 239

(V NH: OH

N: 8 O S 0 3N8.

I S O 3N8.

Purpleblue, Shultz N o. 303 (VII) ('3 O ONa O H NHz S OaNa Green, Shultz No. 681

The color indicated following the above structural formulas corresponds to the color of the dye previous to color development. With the exception of dyes IV and VII above, during color development the azo dyes change in color to light yellow or brown. Dye IV changes to an almost neutral (slightly magenta) color and dye VII changes to a definite yellow color.

The useful 2-azo-1-naphthol dyes can be classified structurally as follows:

wherein Z represents the non-metallic atoms necessary to complete a naphthalene group the 3- and 4positions of which are free of substituents and R represents an aryl group of the benzene or naphthalene series substituted or not, as shown in the above dye formulas.

A representative photographic element contemplated by our invention is shown in greatly enlarged cross-see tional view in Fig. 1 of the accompanying drawing. In Fig. 1, layer 20 represents a film support carrying the silver halide emulsion layers 21, 22 and 23, respectively sensitized to the red, green, and blue regions of the visible spectrum, emulsions 22 and 23 being separated by a yellow filter layer 24in the conventional manner. As shown, emulsion layer 21 contains a colorless cyan-forming coupler, emulsion 23 a colorless yellow-forming coupler and emulsion 22 contains the colorless magenta-forming coupler, a 4-azo-5-pyrazolone coupler and a 2-azo-l-naphthol coupler. The 4-azo-5-pyrazolone coupler is a yellowcolored coupler which gives a magenta dye on color development and the Z-azo-l-naphthol coupler may be a coupler of the invention which is blue in color and gives an almost neutral color in the color development reaction. Accordingly, depending upon the nature and proportion of the 2-azo couplers present in emulsion layer 22, this layer would appear bluish, yellowish or greenish in color.

Fig. 2 illustrates the sensitometric characteristics of the dye images obtainable in an emulsion such as layer 22 containing the mixture of couplers. In Fig. 2, curve 1 represents the green light absorption characteristics of the magenta dye image at various exposure levels, curve 2 the blue light absorption characteristics of the yellow masking image obtained from the 4-azo-5-pyrazolone coupler and curve 3 the red light absorption characteristics of the bluish masking image attributable to the 2- azo-1-naphthol coupler. The preparation of an emulsion layer capable of providing dye images having these characteristics is shown in Example 3 hereinafter.

The preparations of a number of typical emulsion layers are given in the following examples.

EXAMPLE 1 Two and one-half parts of the yellow dye-forming coupler u-{3 [ct-(2,4 di tert.-amylphenoxy)acetamidolbenzoyl}-2-methoxy-acetanilide (McCrossen et al. U. S. patent application Serial No. 575,099, filed March 30, 1956), was dispersed in 170 parts of 10 percent gelatin solution by means of di-n-butyl phthalate by milling in a colloid mill. A solution of 0.4 part of the magenta colored coupler I in dimethyl formamide was added to this dispersion followed by the addition of parts of a gelatinobromoiodide, emulsion. The emulsion was coated in the usual manner on a film base.

The coating was then exposed in the normal manner for sensitometric evaluation and then processed at 70 F. as follows:

The above color developer had the following composition:

G. Sodium hexametaphosphate 1.0 Sodium sulfite (anhydrous) 2.0 2-amino-5-diethylamino toluene HCl 2.0 Potassium bromide 2.0 Sodium carbonate (anhydrous) 20.0

Water to 1 liter.

The above fixing baths were conventional acid-hypo fixers.

I The above bleaching solution contained 50g. potassium ferricyanide and 20 g. potassium bromide per liter of water.

After processing, the image was found to comprise a yellow negative image of varying density and a positive magenta masking image compensating for the improper green light absorption of the yellow image. By varying the ratio of the colored to colorless couplers in such emulsions, the improper absorptions of other yellow dyes can be compensated for in the same manner.

EXAMPLE 2 In the manner of Example 1, an emulsion was prepared and coated containing a dibutyl phthalate dispersion of a mixture of (1) the cyan-forming coupler: 1- hydroxy 2 [6 (2',4' di tert. amylphenoxy) n butyll-naphthamide (Weissberger et al. U. S. Patent 2,474,293, granted June 28, 1949), which yields cyan dyes having unwanted blue and green light absorptions, and (2) the magenta coupler I. Processing in the manner of Example 1 produced a negative cyan dye image in the emulsion layer and a positive magenta mask compensating primarily for the unwanted green light absorption of the cyan dye image. 1

EXAMPLE 3 An emulsion was prepared similar to that shown in layer 22 of Fig. 1 of the drawing by dispersing in aqueous gelatin solution by means of dibutyl phthalate the three couplers (1) the magenta-forming coupler: 1- (2.,4',6 trichlorophenyl) 3 [3" (2"',4"' di-tert. amylphenoxyacetamido) benzamido] 5 -pyrazolone (Loria etal. U. S. Patent 2,600,788, granted June 17,

.1952) yielding dye images having unwanted blue and red light absorptions, (2) a yellow-colored coupler yielding a -magenta dye: 1 7 [p (tert. butylphenoxy)- phenyl] 3 [a p (tert.-butylphenoxy)propionamido- 4-p-methoxyphenylazo)-5-pyrazolone having the formula prepared from coupler No. 47 of the Porter et al. U. S. Patent-2,369,489 by coupling with diazotized p-methoxy aniline by the methods described in the Glass et al. U. S. 'Patent 2,455,170, granted November30, 1948, and (3) the blue coupler IV of the invention added from aqueous alcoholic solution.

A coating of the resulting emulsion processed as described in Example 1 yielded a composite negative magenta dye image from the two magenta couplers above and a composite positive dye masking image composed of the residual yellow-colored pyrazolone coupler and the residual blue-colored 2-azo-1-naphtho1 coupler which composite masking image compensated for unwanted blue and red light absorptions of the negative magenta dye image.

EXAMPLE 4 A multilayer color film similar to that shown in Fig. 1 of the drawing can be prepared by coating a cellulose ester film base with the following:

A. A red-sensitive gelatino-bromoiodide emulsion prepared as described in Example 2 and containing a cyanforming coupler and the magenta-colored coupler I of the invention.

B. A green-sensitive gelatino-bromoiodide emulsion prepared as described in Example 3 and containing the magenta-forming coupler, the yellow-colored magentaforming coupler and the blue coupler IV of the invention.

C. A gelatin layer containing yellow colloidal silver.

D. A blue-sensitive gelatino-bromoiodide emulsion prepared as in Example land containing the yellow dyeforming coupler and the magenta-colored coupler I of the invention.

The resulting film processed as described in Example 1 yields yellow and cyan images in which unwanted green light absorptions are compensated for by magenta masks obtained from coupler I, and magenta dye images in which unwanted blue and red light absorptions are compensated for by a composite mask obtained from the yellow coupler and the blue coupler IV.

The syntheses of the azo dye couplers I, II and III is as follows:

Compound I.-8 amino 5,7 disulfo 2(3-dodecyloxyphenylazo)-l-naphthol disodium salt A mixture of 10 ml. concentrated HCl and 50 ml. H O Was added to a solution of 5 g. (.018 mole) of mdodecyloxyaniline in 75 ml. dioxane. The resulting slurry was cooled to 10 and the amine diazotized by the slow addition of a solution of 3.3 g. of NaNO in 10 ml. H O. When diazotization was complete the solution Was. added dropwise to a cold solution of 5.75 g. (.018 mole) of 8-ami no-5,7-disulfo-l-naphthol (Chicago acid) in 250 ml. H 0 containing 15 g. Na CO The solution was stirred for one hour after addition of the diazonium solution and then concentrated to dryness. The dye was purified by chromotography using activated aluminaas the adsorbent, ethylene glycol as the solvent, and methanol-H O as the eluent.

Compound ll.-m Phenylenebis(8-'amin0-2-azo-5-sulf0- l-naphthol) disodium salt To a solution of 3.26 g. of NaNO in a mixture of 16 ml. HCl, 5.0 ml. H 0 and 20 g. of ice were .added 3.62 g. (.02 mole) of m-phenylenediamine dihydrochloride over a 5-minute period. The temperature of the mixture was kept at -l5 by the addition of Dry Ice when necessary. The diazonium solution was then slowly added to a solution of 9.1 g. (.038 mole) of 8-amino- 5-sulfo-1-naphthol and 17 g. of Na CO in 150 ml. of H 0 with good stirring. After. three hours the dye which had separated from solution was collected on a filter, washed with acetone, and dried. The crude dye was purified in the same manner as Compound I using florisil as the adsorbent in place of activated alumina.

Compound III.8 acetamido 2-(3-d0decyl0xyphenylaz0)-5-sulf0-1-naphth0l disodium salt To a solution of 12.7 g. (.04 mole) of 8-amino-5- sulfo-l-naphthol and 4 g. of Na CO in ml. of H 0 was added 13.6 g. of acetic anhydride over a 15-minute period. Then 12 g. of Na CO was added and the mixture heated on the steam bath for 2 hours. The

solution was then diluted with 125 ml. of H and cooled.

Meanwhile,.l0 g., (.036 mole) of rn-dodecyloxyaniline was diazotized (as above). The diazonium solution was added slowly to the solution of the acetylated 8- amino-S-sulfo-l-naphthol. After one hour, the dye which precipitated was collected on a filter, washed with acetonitrile, and finally recrystallized from 300 ml. of butanol.

The photographic emulsions containing the azo dye couplers of the invention in conjunction with colorless couplers and, if desired, other colored couplers, comprise the usual silver halides and mixtures of silver halides such as silver bromide, chloride, bromoiodide and chlorobromidc emulsions. The emulsion vehicles include the usual hydrophilic colloids such as gelatin, polyvinyl alcohol, hydrolyzed cellulose esters and other natural and synthetic hydrophilic colloids.

The emulsions containing the coupler compounds can be used in both negative and reversal processes of color photography contemplated by the claims hereinafter. In the former case, color development takes place following image exposure. In the reversal process, color development follows image exposure, black-and-white development and reversal exposure steps.

The coupler compounds of the invention can be incorporated into the emulsions by use of organic solvents or aqueous solutions depending upon the solubility of the alkali metal salts of the couplers containing sulfonic acid groups. Coupler solvents can be used as shown in U. S. Patents 2,304,940 and 2,322,027 to facilitate the incorporation of the couplers into emulsions.

The color developing agents useful for the development of the emulsions and carrying out the processes of the invention are those Well known in the art, particularly the p-phenylenediamine and aminophenol compounds having a primary aromatic amino group which enables the oxidation product of the color developer to couple with the mentioned coupler compounds.

What we claim is:

l. A silver halide emulsion layer containing a colorless coupler compound capable of reaction with the oxidation product of a. primary aromatic amino silver halide developing agent to form a dye, and a 2-azo-l-naphthol dye the 3- and 4-positions of which are free of substituents.

2. A multilayer photographic color film comprising a plurality of superposed differentially light-sensitive silver halide emulsion layers containing colorless coupler compounds capable of reaction with the oxidation products of a primary aromatic amino silver halide developing agent for the formation of subtractively colored dye images in the respective emulsion layers, at least one of said emulsion layers containing in addition to said colorless coupler compound a 2-azo-l-naphthol dye the 3- and 4-positions of which are free of substituents.

3. The emulsion of claim 1 containing in addition a colored coupler compound capable of reaction with the oxidation products of a primary aromatic amino silver halide developing agent to form a dye having a color different from the specified 2=azo-1-naphthol dye.

4. A multilayer photographic color film comprising a plurality of superposed differentially light-sensitive silver halide emulsion layerscont'aining colorless coupler compounds capable of reaction with the oxidation products of a primary aromatic amino silver halide developing agent for the formation of subtractively colored dye images in the respective emulsion layers, at least one of said emulsion layers containing in addition to said colorless coupler compound a Z-aZo-l-naphthol dye the 3- and 4-positions of which are free of substituents, and a colored coupler compound capable of forming a dye image of substantially the same color as said colorless coupler.

5. A method for forming a photographic color'correction image which comprises locally exposing a silver halide emulsion layer containing a mixture of a colorless coupler compound capable of reaction with the oxidation product of a primary aromatic amino silver halide developing agent to form a dye, and a 2-azo 1-naphthol dye the 3- and 4-positions of which are free of substituents, developing the exposed emulsion layer with said developer agent until there is obtained in the exposed region of the emulsion layer a composite dye image composed of the reaction products of said developing agent with said colorless coupler and said 2-azo*1=naphthol dye, the 2-aZo-l-naphtl1ol dye remaining substantially unchanged in the unexposed region of the emulsion layer as the result of color development.

6. The process of claim 5 wherein the emulsion layer contains in addition to the specified colorless coupler and the 2'-az'o=1-naphthol dye, a colored coupler compound capable of reaction wth the oxidation products of a primary aromatic amino silver halide developing agent to form a dye having a color different from the 2- azo-l-naphthol dye.

7. The process of claim 5 wherein the emulsion layer contains in addition to the specified colorless coupler and the Z-azo-l-naphthol dye, a colored coupler compound capable of reaction with the oxidation products of a primary aromatic amino silver halide developing agent to form a dye image of substantially the same color as formed by said colorless coupler.

References Cited in the file of this patent UNITED STATES PATENTS 2,286,714 Chechak June 16, 1942 2,304,884 Carroll Dec. 15, 1942 2,428,054 Vitt'um et al. Sept. 30, 1947 2,694,636 Keller Nov. 16, 1954 

5. A METHOD FOR FORMING A PHOTOGRAPHIC COLOR-CORRECTION IMAGE WHICH COMPRISES LOCALLY EXPOSING A SILVER HALIDE EMULSION LAYER CONTAINING A MIXTURE OF A COLORLESS COUPLER COMPOUND CAPABLE OF REACTION WITH THE OXIDATION PRODUCT OF A PRIMARY AROMATIC AMINO SILVER HALIDE DEVELOPING AGENT TO FORM A DYE, AND A 2-ZAO-1-NAPHTOL DYE THE 3- AND 4-POSITIONS OF WHICH ARE FREE OF SUBSTITUENTS, DEVELOPING THE EXPOSED EMULSION LAYER WITH SAID DEVELOPER AGENT UNTIL THERE IS OBTAINED IN THE EXPOSED REGION OF THE EMULSION LAYER A COMPOSITE DYE IMAGE COMPOSED OF THE REACTION PRODUTS OF SAID DEVELOPING AGENT WITH SAID COLORIES COUPLER AND SAID 2-AZO-1-NAPHTHOL DYE, THE 2-AZE-1-NAPTHOL DYE REMAINING SUBSTANTIALLY UNCHANGED IN THE UNEXOSED REGION OF THE EMULSION LAYER AS THE RESULT OF COLOR DEVELOPMENT. 